Haematological consequences of acute uncomplicated falciparum malaria: a WorldWide Antimalarial Resistance Network pooled analysis of individual patient data

BACKGROUND

Plasmodium falciparum malaria is associated with anaemia-related morbidity, attributable to host, parasite and drug factors. We quantified the haematological response following treatment of uncomplicated P. falciparum malaria to identify the factors associated with malarial anaemia.

METHODS

Individual patient data from eligible antimalarial efficacy studies of uncomplicated P. falciparum malaria, available through the WorldWide Antimalarial Resistance Network data repository prior to August 2015, were pooled using standardised methodology. The haematological response over time was quantified using a multivariable linear mixed effects model with nonlinear terms for time, and the model was then used to estimate the mean haemoglobin at day of nadir and day 7. Multivariable logistic regression quantified risk factors for moderately severe anaemia (haemoglobin < 7 g/dL) at day 0, day 3 and day 7 as well as a fractional fall ≥ 25% at day 3 and day 7.

RESULTS

A total of 70,226 patients, recruited into 200 studies between 1991 and 2013, were included in the analysis: 50,859 (72.4%) enrolled in Africa, 18,451 (26.3%) in Asia and 916 (1.3%) in South America. The median haemoglobin concentration at presentation was 9.9 g/dL (range 5.0-19.7 g/dL) in Africa, 11.6 g/dL (range 5.0-20.0 g/dL) in Asia and 12.3 g/dL (range 6.9-17.9 g/dL) in South America. Moderately severe anaemia (Hb < 7g/dl) was present in 8.4% (4284/50,859) of patients from Africa, 3.3% (606/18,451) from Asia and 0.1% (1/916) from South America. The nadir haemoglobin occurred on day 2 post treatment with a mean fall from baseline of 0.57 g/dL in Africa and 1.13 g/dL in Asia. Independent risk factors for moderately severe anaemia on day 7, in both Africa and Asia, included moderately severe anaemia at baseline (adjusted odds ratio (AOR) = 16.10 and AOR = 23.00, respectively), young age (age < 1 compared to ≥ 12 years AOR = 12.81 and AOR = 6.79, respectively), high parasitaemia (AOR = 1.78 and AOR = 1.58, respectively) and delayed parasite clearance (AOR = 2.44 and AOR = 2.59, respectively). In Asia, patients treated with an artemisinin-based regimen were at significantly greater risk of moderately severe anaemia on day 7 compared to those treated with a non-artemisinin-based regimen (AOR = 2.06 [95%CI 1.39-3.05], p < 0.001).

CONCLUSIONS

In patients with uncomplicated P. falciparum malaria, the nadir haemoglobin occurs 2 days after starting treatment. Although artemisinin-based treatments increase the rate of parasite clearance, in Asia they are associated with a greater risk of anaemia during recovery.

Uganda's experience in Ebola virus disease outbreak preparedness, 2018-2019

BACKGROUND

Since the declaration of the 10th Ebola Virus Disease (EVD) outbreak in DRC on 1st Aug 2018, several neighboring countries have been developing and implementing preparedness efforts to prevent EVD cross-border transmission to enable timely detection, investigation, and response in the event of a confirmed EVD outbreak in the country. We describe Uganda's experience in EVD preparedness.

RESULTS

On 4 August 2018, the Uganda Ministry of Health (MoH) activated the Public Health Emergency Operations Centre (PHEOC) and the National Task Force (NTF) for public health emergencies to plan, guide, and coordinate EVD preparedness in the country. The NTF selected an Incident Management Team (IMT), constituting a National Rapid Response Team (NRRT) that supported activation of the District Task Forces (DTFs) and District Rapid Response Teams (DRRTs) that jointly assessed levels of preparedness in 30 designated high-risk districts representing category 1 (20 districts) and category 2 (10 districts). The MoH, with technical guidance from the World Health Organisation (WHO), led EVD preparedness activities and worked together with other ministries and partner organisations to enhance community-based surveillance systems, develop and disseminate risk communication messages, engage communities, reinforce EVD screening and infection prevention measures at Points of Entry (PoEs) and in high-risk health facilities, construct and equip EVD isolation and treatment units, and establish coordination and procurement mechanisms.

CONCLUSION

As of 31 May 2019, there was no confirmed case of EVD as Uganda has continued to make significant and verifiable progress in EVD preparedness. There is a need to sustain these efforts, not only in EVD preparedness but also across the entire spectrum of a multi-hazard framework. These efforts strengthen country capacity and compel the country to avail resources for preparedness and management of incidents at the source while effectively cutting costs of using a "fire-fighting" approach during public health emergencies.

The effect of dosing strategies on the therapeutic efficacy of artesunate-amodiaquine for uncomplicated malaria: a meta-analysis of individual patient data

BACKGROUND

Artesunate-amodiaquine (AS-AQ) is one of the most widely used artemisinin-based combination therapies (ACTs) to treat uncomplicated Plasmodium falciparum malaria in Africa. We investigated the impact of different dosing strategies on the efficacy of this combination for the treatment of falciparum malaria.

METHODS

Individual patient data from AS-AQ clinical trials were pooled using the WorldWide Antimalarial Resistance Network (WWARN) standardised methodology. Risk factors for treatment failure were identified using a Cox regression model with shared frailty across study sites.

RESULTS

Forty-three studies representing 9,106 treatments from 1999-2012 were included in the analysis; 4,138 (45.4%) treatments were with a fixed dose combination with an AQ target dose of 30 mg/kg (FDC), 1,293 (14.2%) with a non-fixed dose combination with an AQ target dose of 25 mg/kg (loose NFDC-25), 2,418 (26.6%) with a non-fixed dose combination with an AQ target dose of 30 mg/kg (loose NFDC-30), and the remaining 1,257 (13.8%) with a co-blistered non-fixed dose combination with an AQ target dose of 30 mg/kg (co-blistered NFDC). The median dose of AQ administered was 32.1 mg/kg [IQR: 25.9-38.2], the highest dose being administered to patients treated with co-blistered NFDC (median = 35.3 mg/kg [IQR: 30.6-43.7]) and the lowest to those treated with loose NFDC-25 (median = 25.0 mg/kg [IQR: 22.7-25.0]). Patients treated with FDC received a median dose of 32.4 mg/kg [IQR: 27-39.0]. After adjusting for reinfections, the corrected antimalarial efficacy on day 28 after treatment was similar for co-blistered NFDC (97.9% [95% confidence interval (CI): 97.0-98.8%]) and FDC (98.1% [95% CI: 97.6%-98.5%]; P = 0.799), but significantly lower for the loose NFDC-25 (93.4% [95% CI: 91.9%-94.9%]), and loose NFDC-30 (95.0% [95% CI: 94.1%-95.9%]) (P < 0.001 for all comparisons). After controlling for age, AQ dose, baseline parasitemia and region; treatment with loose NFDC-25 was associated with a 3.5-fold greater risk of recrudescence by day 28 (adjusted hazard ratio, AHR = 3.51 [95% CI: 2.02-6.12], P < 0.001) compared to FDC, and treatment with loose NFDC-30 was associated with a higher risk of recrudescence at only three sites.

CONCLUSIONS

There was substantial variation in the total dose of amodiaquine administered in different AS-AQ combination regimens. Fixed dose AS-AQ combinations ensure optimal dosing and provide higher antimalarial treatment efficacy than the loose individual tablets in all age categories.

Artesunate plus pyronaridine for treating uncomplicated Plasmodium falciparum malaria

BACKGROUND

The World Health Organization (WHO) recommends that people with uncomplicated Plasmodium falciparum malaria are treated using Artemisinin-based Combination Therapy (ACT). ACT combines three-days of a short-acting artemisinin derivative with a longer-acting antimalarial which has a different mode of action. Pyronaridine has been reported as an effective antimalarial over two decades of use in parts of Asia, and is currently being evaluated as a partner drug for artesunate.

OBJECTIVES

To evaluate the efficacy and safety of artesunate-pyronaridine compared to alternative ACTs for treating people with uncomplicated P. falciparum malaria.

SEARCH METHODS

We searched the Cochrane Infectious Diseases Group Specialized Register; Cochrane Central Register of Controlled Trials (CENTRAL), published in The Cochrane Library; MEDLINE; EMBASE; LILACS; ClinicalTrials.gov; the metaRegister of Controlled Trials (mRCT); and the WHO International Clinical Trials Search Portal up to 16 January 2014. We searched reference lists and conference abstracts, and contacted experts for information about ongoing and unpublished trials.

SELECTION CRITERIA

Randomized controlled trials of artesunate-pyronaridine versus other ACTs in adults and children with uncomplicated P. falciparum malaria.For the safety analysis, we also included adverse events data from trials comparing any treatment regimen containing pyronaridine with regimens not containing pyronaridine.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial eligibility and risk of bias, and extracted data. We combined dichotomous data using risk ratios (RR) and continuous data using mean differences (MD), and presented all results with a 95% confidence interval (CI). We used the GRADE approach to assess the quality of evidence.

MAIN RESULTS

We included six randomized controlled trials enrolling 3718 children and adults. Artesunate-pyronaridine versus artemether-lumefantrineIn two multicentre trials, enrolling mainly older children and adults from west and south-central Africa, both artesunate-pyronaridine and artemether-lumefantrine had fewer than 5% PCR adjusted treatment failures during 42 days of follow-up, with no differences between groups (two trials, 1472 participants, low quality evidence). There were fewer new infections during the first 28 days in those given artesunate-pyronaridine (PCR-unadjusted treatment failure: RR 0.60, 95% CI 0.40 to 0.90, two trials, 1720 participants, moderate quality evidence), but no difference was detected over the whole 42 day follow-up (two trials, 1691 participants, moderate quality evidence). Artesunate-pyronaridine versus artesunate plus mefloquineIn one multicentre trial, enrolling mainly older children and adults from South East Asia, both artesunate-pyronaridine and artesunate plus mefloquine had fewer than 5% PCR adjusted treatment failures during 28 days follow-up (one trial, 1187 participants, moderate quality evidence). PCR-adjusted treatment failures were 6% by day 42 for these treated with artesunate-pyronaridine, and 4% for those with artesunate-mefloquine (RR 1.64, 95% CI 0.89 to 3.00, one trial, 1116 participants, low quality evidence). Again, there were fewer new infections during the first 28 days in those given artesunate-pyronaridine (PCR-unadjusted treatment failure: RR 0.35, 95% CI 0.17 to 0.73, one trial, 1720 participants, moderate quality evidence), but no differences were detected over the whole 42 days (one trial, 1146 participants, low quality evidence). Adverse effectsSerious adverse events were uncommon in these trials, with no difference detected between artesunate-pyronaridine and comparator ACTs. The analysis of liver function tests showed biochemical elevation were four times more frequent with artesunate-pyronaridine than with the other antimalarials (RR 4.17, 95% CI 1.38 to 12.62, four trials, 3523 participants, moderate quality evidence).

AUTHORS' CONCLUSIONS

Artesunate-pyronaridine performed well in these trials compared to artemether-lumefantrine and artesunate plus mefloquine, with PCR-adjusted treatment failure at day 28 below the 5% standard set by the WHO. Further efficacy and safety studies in African and Asian children are required to clarify whether this combination is an option for first-line treatment.

WITHDRAWN: Azithromycin for treating uncomplicated typhoid and paratyphoid fever (enteric fever)

BACKGROUND

Review status: Current question - no update intended. Azithromycin treatments are included in the review: Fluoroquinolones for treating typhoid and paratyphoid fever (enteric fever). (Thaver D, Zaidi AKM, Critchley JA, Azmatullah A, Madni SA, Bhutta ZA. Fluoroquinolones for treating typhoid and paratyphoid fever (enteric fever). Cochrane Database of Systematic Reviews 2008, Issue 4. Art. No.: CD004530. DOI: 10.1002/14651858.CD004530.pub3.)   This latter review is being updated, and will be published in late 2011.Enteric fever (typhoid and paratyphoid fever) is potentially fatal. Infection with drug-resistant strains of the causative organism Salmonella enterica serovar Typhi or Paratyphi increases morbidity and mortality. Azithromycin may have better outcomes in people with uncomplicated forms of the disease.

OBJECTIVES

To compare azithromycin with other antibiotics for treating uncomplicated enteric fever.

SEARCH STRATEGY

In August 2008, we searched the Cochrane Infectious Diseases Group Specialized Register, CENTRAL (The Cochrane Library 2008, Issue 3), MEDLINE, EMBASE, LILACS, and mRCT. We also searched conference proceedings, reference lists, and contacted researchers and a pharmaceutical company.

SELECTION CRITERIA

Randomized controlled trials comparing azithromycin with other antibiotics for treating children and adults with uncomplicated enteric fever confirmed by cultures of S. Typhi or Paratyphi in blood and/or stool.

DATA COLLECTION AND ANALYSIS

Both authors independently extracted data and assessed the risk of bias. Dichotomous data were presented and compared using the odds ratio, and continuous data were reported as arithmetic means with standard deviations and were combined using the mean difference (MD). Both were presented with 95% confidence intervals (CI).

MAIN RESULTS

Seven trials involving 773 participants met the inclusion criteria. The trials used adequate methods to generate the allocation sequence and conceal allocation, and were open label. Three trials exclusively included adults, two included children, and two included both adults and children; all were hospital inpatients. One trial evaluated azithromycin against chloramphenicol and did not demonstrate a difference for any outcome (77 participants, 1 trial). When compared with fluoroquinolones in four trials, azithromycin significantly reduced clinical failure (OR 0.48, 95% CI 0.26 to 0.89; 564 participants, 4 trials) and duration of hospital stay (MD -1.04 days, 95% CI -1.73 to -0.34 days; 213 participants, 2 trials); all four trials included people with multiple-drug-resistant or nalidixic acid-resistant strains of S. Typhi or S. Paratyphi. We detected no statistically significant difference in the other outcomes. Compared with ceftriaxone, azithromycin significantly reduced relapse (OR 0.09, 95% CI 0.01 to 0.70; 132 participants, 2 trials) and not other outcome measures. Few adverse events were reported, and most were mild and self limiting.

AUTHORS' CONCLUSIONS

Azithromycin appears better than fluoroquinolone drugs in populations that included participants with drug-resistant strains. Azithromycin may perform better than ceftriaxone.

Improved malaria case management through the implementation of a health facility-based sentinel site surveillance system in Uganda

BACKGROUND

Heath facility-based sentinel site surveillance has been proposed as a means of monitoring trends in malaria morbidity but may also provide an opportunity to improve malaria case management. Here we described the impact of a sentinel site malaria surveillance system on promoting laboratory testing and rational antimalarial drug use.

METHODOLOGY/PRINCIPAL FINDINGS

Sentinel site malaria surveillance was established at six health facilities in Uganda between September 2006 and January 2007. Data were collected from all patients presenting to the outpatient departments including demographics, laboratory results, diagnoses, and treatments prescribed. Between the start of surveillance and March 2010, a total 424,701 patients were seen of which 229,375 (54%) were suspected of having malaria. Comparing the first three months with the last three months of surveillance, the proportion of patients with suspected malaria who underwent diagnostic testing increased from 39% to 97% (p<0.001). The proportion of patients with an appropriate decision to prescribe antimalarial therapy (positive test result prescribed, negative test result not prescribed) increased from 64% to 95% (p<0.001). The proportion of patients appropriately prescribed antimalarial therapy who were prescribed the recommended first-line regimen artemether-lumefantrine increased from 48% to 69% (p<0.001).

CONCLUSIONS/SIGNIFICANCE

The establishment of a sentinel site malaria surveillance system in Uganda achieved almost universal utilization of diagnostic testing in patients with suspected malaria and appropriate decisions to prescribed antimalarial based on test results. Less success was achieved in promoting prescribing practice for the recommended first-line therapy. This system could provide a model for improving malaria case management in other health facilities in Africa.

Heterogeneities and consequences of Plasmodium species and hookworm coinfection: a population based study in Uganda

Background. Previous studies have suggested that helminth infection exacerbates malaria, but few existing epidemiological studies adequately control for infection heterogeneities and confounding factors. In this study, we investigate spatial and household heterogeneities, predictors, and consequences of Plasmodium species and hookworm coinfection in rural communities in Uganda.

Methods. A cross-sectional study was conducted among 1770 individuals aged 0–88 years in 4 villages. We recorded demographic, socioeconomic, and microgeographic factors during household surveys. We determined malaria parasitemia and hemoglobin concentration and collected stool samples on 2 consecutive days. For data analysis, we used a hierarchical, spatially explicit Bayesian framework.

Results. Prevalence of Plasmodium-hookworm coinfection was 15.5% overall and highest among school-aged children. We found strong evidence of spatial and household clustering of coinfection and an enduring positive association between Plasmodium-species and hookworm infection among preschool-aged children (odds ratio [OR], 2.36; 95% Bayesian credible interval [BCI], 1.26–4.30) and adults (OR, 2.09; 95% BCI, 1.35–3.16) but not among school-aged children. Coinfection was associated with lower hemoglobin level only among school-aged children.

Conclusions.Plasmodium-hookworm coinfection exhibits marked age dependency and significant spatial and household heterogeneity, and among preschool-aged children and adults, occurs more than would be expected by chance. Such heterogeneities provide insight into factors underlying observed patterns and the design of integrated control strategies.

Heritability of Plasmodium parasite density in a rural Ugandan community

Many factors influence variation in Plasmodium infection levels, including parasite/host genetics, immunity, and exposure. Here, we examine the roles of host genetics and exposure in determining parasite density, and test whether effects differ with age. Data for 1,711 residents of an eastern Ugandan community were used in pedigree-based variance component analysis. Heritability of parasite density was 13% (P < 0.001) but was not significant after controlling for shared household. Allowing variance components to vary between children (< 16 years) and adults (≥ 16 years) revealed striking age differences; 26% of variation could be explained by additively acting genes in children (P < 0.001), but there was no genetic involvement in adults. Domestic environment did not explain variation in children and explained 5% in adults (P = 0.09). Genetic effects are an important determinant of parasite density in children in this population, consistent with previous quantitative genetic studies of Plasmodium parasitaemia, although differences in environmental exposure play a lesser role.

Plasmodium infection and its risk factors in eastern Uganda

BACKGROUND

Malaria is a leading cause of disease burden in Uganda, although surprisingly few contemporary, age-stratified data exist on malaria epidemiology in the country. This report presents results from a total population survey of malaria infection and intervention coverage in a rural area of eastern Uganda, with a specific focus on how risk factors differ between demographic groups in this population.

METHODS

In 2008, a cross-sectional survey was conducted in four contiguous villages in Mulanda, sub-county in Tororo district, eastern Uganda, to investigate the epidemiology and risk factors of Plasmodium species infection. All permanent residents were invited to participate, with blood smears collected from 1,844 individuals aged between six months and 88 years (representing 78% of the population). Demographic, household and socio-economic characteristics were combined with environmental data using a Geographical Information System. Hierarchical models were used to explore patterns of malaria infection and identify individual, household and environmental risk factors.

RESULTS

Overall, 709 individuals were infected with Plasmodium, with prevalence highest among 5-9 year olds (63.5%). Thin films from a random sample of 20% of parasite positive participants showed that 94.0% of infections were Plasmodium falciparum and 6.0% were P. malariae; no other species or mixed infections were seen. In total, 68% of households owned at least one mosquito although only 27% of school-aged children reported sleeping under a net the previous night. In multivariate analysis, infection risk was highest amongst children aged 5-9 years and remained high in older children. Risk of infection was lower for those that reported sleeping under a bed net the previous night and living more than 750 m from a rice-growing area. After accounting for clustering within compounds, there was no evidence for an association between infection prevalence and socio-economic status, and no evidence for spatial clustering.

CONCLUSION

These findings demonstrate that mosquito net usage remains inadequate and is strongly associated with risk of malaria among school-aged children. Infection risk amongst adults is influenced by proximity to potential mosquito breeding grounds. Taken together, these findings emphasize the importance of increasing net coverage, especially among school-aged children.

Use of the slide positivity rate to estimate changes in malaria incidence in a cohort of Ugandan children

Background

As malaria control efforts intensify, it is critical to monitor trends in disease burden and measure the impact of interventions. A key surveillance indicator is the incidence of malaria. Yet measurement of incidence is challenging. The slide positivity rate (SPR) has been used as a surrogate measure of malaria incidence, but limited data exist on the relationship between SPR and the incidence of malaria.

Methods

A cohort of 690 children aged 1-10 years at enrollment were followed for all their health care needs over a four-year period in Kampala, Uganda. All children with fever underwent laboratory testing, allowing us to measure the incidence of malaria and non-malaria fevers. A formula was derived to estimate relative changes in the incidence of malaria (rΔIm) based on changes in the SPR and the assumption that the incidence of non-malaria fevers was consistent over time. Observed and estimated values of rΔIm were compared over two, six, and 12 month time intervals after restricting the analysis to children contributing observation time between the ages of 4-10 years to control for aging of the cohort.

Results

Over the four-year observation period the incidence of malaria declined significantly from 0.93 episodes per person-year in 2005 to 0.39 episodes per person-year in 2008 (p < 0.0001) and the incidence of non-malaria fevers declined significantly from 2.31 episodes per person-year in 2005 to 1.31 episodes per person-year in 2008 (p < 0.0001). Younger age was associated with a significantly greater incidence of malaria and the incidence of malaria was significantly higher during seasonal peaks occurring each January-February and May-June. Changes in SPR produced reasonably accurate estimates of rΔIm over all time intervals. The average absolute difference in observed and estimated values of rΔIm was lower for six-month intervals (0.13) than it was for two-month (0.21) or 12 month intervals (0.21).

Conclusion

Changes in SPR provided a useful estimate of changes in the incidence of malaria in a well defined cohort; however, a gradual decline in the incidence of non-malaria fevers introduced some bias in these estimates.

Efficacy of artesunate-amodiaquine for treating uncomplicated falciparum malaria in sub-Saharan Africa: a multi-centre analysis

BACKGROUND

Artesunate and amodiaquine (AS&AQ) is at present the world's second most widely used artemisinin-based combination therapy (ACT). It was necessary to evaluate the efficacy of ACT, recently adopted by the World Health Organization (WHO) and deployed over 80 countries, in order to make an evidence-based drug policy.

METHODS

An individual patient data (IPD) analysis was conducted on efficacy outcomes in 26 clinical studies in sub-Saharan Africa using the WHO protocol with similar primary and secondary endpoints.

RESULTS

A total of 11,700 patients (75% under 5 years old), from 33 different sites in 16 countries were followed for 28 days. Loss to follow-up was 4.9% (575/11,700). AS&AQ was given to 5,897 patients. Of these, 82% (4,826/5,897) were included in randomized comparative trials with polymerase chain reaction (PCR) genotyping results and compared to 5,413 patients (half receiving an ACT). AS&AQ and other ACT comparators resulted in rapid clearance of fever and parasitaemia, superior to non-ACT. Using survival analysis on a modified intent-to-treat population, the Day 28 PCR-adjusted efficacy of AS&AQ was greater than 90% (the WHO cut-off) in 11/16 countries. In randomized comparative trials (n = 22), the crude efficacy of AS&AQ was 75.9% (95% CI 74.6-77.1) and the PCR-adjusted efficacy was 93.9% (95% CI 93.2-94.5). The risk (weighted by site) of failure PCR-adjusted of AS&AQ was significantly inferior to non-ACT, superior to dihydroartemisinin-piperaquine (DP, in one Ugandan site), and not different from AS+SP or AL (artemether-lumefantrine). The risk of gametocyte appearance and the carriage rate of AS&AQ was only greater in one Ugandan site compared to AL and DP, and lower compared to non-ACT (p = 0.001, for all comparisons). Anaemia recovery was not different than comparator groups, except in one site in Rwanda where the patients in the DP group had a slower recovery.

CONCLUSION

AS&AQ compares well to other treatments and meets the WHO efficacy criteria for use against falciparum malaria in many, but not all, the sub-Saharan African countries where it was studied. Efficacy varies between and within countries. An IPD analysis can inform general and local treatment policies. Ongoing monitoring evaluation is required.

Improved malaria case management after integrated team-based training of health care workers in Uganda

Malaria case management in Africa is characterized by presumptive treatment and substantial overtreatment. We evaluated an integrated team-based training program on malaria case management. Surveillance data 120 days before and after training were compared at eight health facilities in Uganda. After training, the proportion of patients with suspected malaria referred for blood smears increased from 38.3% to 54.6% (P=0.04) in persons<5 years of age years and from 34.1% to 53.4% (P=0.02) in those>or=5 years of age. The proportion of patients with negative blood smears prescribed antimalarial drugs decreased from 47.9% to 19.6% (P<0.001) in persons<5 years of age and from 38.8% to 15.6% (P<0.001) in those>or=5 years of age. Training did not improve the proportion of patients with positive blood smears prescribed antimalarial drugs, the proportion of patients prescribed appropriate antimalarial drugs, or the diagnostic accuracy of microscopy. Integrated team-based training may improve malaria case management and reduce the number of unnecessary antimalarial treatments.

Azithromycin for treating uncomplicated typhoid and paratyphoid fever (enteric fever)

BACKGROUND

Enteric fever (typhoid and paratyphoid fever) is potentially fatal. Infection with drug-resistant strains of the causative organism Salmonella enterica serovar Typhi or Paratyphi increases morbidity and mortality. Azithromycin may have better outcomes in people with uncomplicated forms of the disease.

OBJECTIVES

To compare azithromycin with other antibiotics for treating uncomplicated enteric fever.

SEARCH STRATEGY

In August 2008, we searched the Cochrane Infectious Diseases Group Specialized Register, CENTRAL (The Cochrane Library 2008, Issue 3), MEDLINE, EMBASE, LILACS, and mRCT. We also searched conference proceedings, reference lists, and contacted researchers and a pharmaceutical company.

SELECTION CRITERIA

Randomized controlled trials comparing azithromycin with other antibiotics for treating children and adults with uncomplicated enteric fever confirmed by cultures of S. Typhi or Paratyphi in blood and/or stool.

DATA COLLECTION AND ANALYSIS

Both authors independently extracted data and assessed the risk of bias. Dichotomous data were presented and compared using the odds ratio, and continuous data were reported as arithmetic means with standard deviations and were combined using the mean difference (MD). Both were presented with 95% confidence intervals (CI).

MAIN RESULTS

Seven trials involving 773 participants met the inclusion criteria. The trials used adequate methods to generate the allocation sequence and conceal allocation, and were open label. Three trials exclusively included adults, two included children, and two included both adults and children; all were hospital inpatients. One trial evaluated azithromycin against chloramphenicol and did not demonstrate a difference for any outcome (77 participants, 1 trial). When compared with fluoroquinolones in four trials, azithromycin significantly reduced clinical failure (OR 0.48, 95% CI 0.26 to 0.89; 564 participants, 4 trials) and duration of hospital stay (MD -1.04 days, 95% CI -1.73 to -0.34 days; 213 participants, 2 trials); all four trials included people with multiple-drug-resistant or nalidixic acid-resistant strains of S. Typhi or S. Paratyphi. We detected no statistically significant difference in the other outcomes. Compared with ceftriaxone, azithromycin significantly reduced relapse (OR 0.09, 95% CI 0.01 to 0.70; 132 participants, 2 trials) and not other outcome measures. Few adverse events were reported, and most were mild and self limiting.

AUTHORS' CONCLUSIONS

Azithromycin appears better than fluoroquinolone drugs in populations that included participants with drug-resistant strains. Azithromycin may perform better than ceftriaxone.

Different methodological approaches to the assessment of in vivo efficacy of three artemisinin-based combination antimalarial treatments for the treatment of uncomplicated falciparum malaria in African children

Background

Use of different methods for assessing the efficacy of artemisinin-based combination antimalarial treatments (ACTs) will result in different estimates being reported, with implications for changes in treatment policy.

Methods

Data from different in vivo studies of ACT treatment of uncomplicated falciparum malaria were combined in a single database. Efficacy at day 28 corrected by PCR genotyping was estimated using four methods. In the first two methods, failure rates were calculated as proportions with either (1a) reinfections excluded from the analysis (standard WHO per-protocol analysis) or (1b) reinfections considered as treatment successes. In the second two methods, failure rates were estimated using the Kaplan-Meier product limit formula using either (2a) WHO (2001) definitions of failure, or (2b) failure defined using parasitological criteria only.

Results

Data analysed represented 2926 patients from 17 studies in nine African countries. Three ACTs were studied: artesunate-amodiaquine (AS+AQ, N = 1702), artesunate-sulphadoxine-pyrimethamine (AS+SP, N = 706) and artemether-lumefantrine (AL, N = 518).

Using method (1a), the day 28 failure rates ranged from 0% to 39.3% for AS+AQ treatment, from 1.0% to 33.3% for AS+SP treatment and from 0% to 3.3% for AL treatment. The median [range] difference in point estimates between method 1a (reference) and the others were: (i) method 1b = 1.3% [0 to24.8], (ii) method 2a = 1.1% [0 to21.5], and (iii) method 2b = 0% [-38 to19.3].

The standard per-protocol method (1a) tended to overestimate the risk of failure when compared to alternative methods using the same endpoint definitions (methods 1b and 2a). It either overestimated or underestimated the risk when endpoints based on parasitological rather than clinical criteria were applied. The standard method was also associated with a 34% reduction in the number of patients evaluated compared to the number of patients enrolled. Only 2% of the sample size was lost when failures were classified on the first day of parasite recurrence and survival analytical methods were used.

Conclusion

The primary purpose of an in vivo study should be to provide a precise estimate of the risk of antimalarial treatment failure due to drug resistance. Use of survival analysis is the most appropriate way to estimate failure rates with parasitological recurrence classified as treatment failure on the day it occurs.

Pharmacovigilance of antimalarial treatment in Uganda: community perceptions and suggestions for reporting adverse events

OBJECTIVES

The deployment of new antimalarials in Africa provides an important opportunity to develop systems for pharmacovigilance. To inform strategies for reporting adverse events in Uganda, we investigated local perceptions and experiences with antimalarial treatment, and evaluated existing and potential systems for pharmacovigilance.

METHODS

Focus group discussions (FGD) were conducted with community members and health workers from urban and rural Uganda exploring knowledge of fever/malaria, perceptions and expectations of treatment, understanding of adverse effects, and experiences with adverse events. Sessions were recorded, transcribed into English, and analysed using a coding scheme developed from pre-defined topics together with themes emerging from the data.

RESULTS

Between April and July 2006, we conducted 25 FGDs; 16 with community members and nine with health workers. All respondents had extensive experience with malaria and its treatment. Community members commonly recognized adverse effects of antimalarial therapy. However, events were uncommonly reported, and certain events were often interpreted as signs of successful treatment. Community members often felt that the costs of reporting or seeking additional care outweighed the potential benefits. Health workers were unfamiliar with formal pathways for reporting, and were deterred by the additional work of reporting and fear of incrimination. Respondents provided suggestions for incentives and methods of reporting, emphasizing that pharmacovigilance should ideally encompass the public and private sector, and the community.

CONCLUSIONS

To be successful, pharmacovigilance relying on voluntary reporting will require active participation of patients and health workers. Addressing the costs and benefits of reporting, and providing sensitization, training and feedback will be important.

Monitoring antimalarial safety and tolerability in clinical trials: a case study from Uganda

Background

New antimalarial regimens, including artemisinin-based combination therapies (ACTs), have been adopted widely as first-line treatment for uncomplicated malaria. Although these drugs appear to be safe and well-tolerated, experience with their use in Africa is limited and continued assessment of safety is a priority. However, no standardized guidelines for evaluating drug safety and tolerability in malaria studies exist. A system for monitoring adverse events in antimalarial trials conducted in Uganda was developed. Here the reporting system is described, and difficulties faced in analysing and interpreting the safety results are illustrated, using data from the trials.

Case description

Between 2002 and 2007, eleven randomized, controlled clinical trials were conducted to compare the efficacy, safety, and tolerability of different antimalarial regimens for treatment of uncomplicated malaria in Uganda. The approach to adverse event monitoring was similar in all studies. A total of 5,614 treatments were evaluated in 4,876 patients. Differences in baseline characteristics and patterns of adverse event reporting were noted between the sites, which limited the ability to pool and analyse data. Clinical failure following antimalarial treatment confounded associations between treatment and adverse events that were also common symptoms of malaria, particularly in areas of lower transmission intensity.

Discussion and evaluation

Despite prospectively evaluating for adverse events, limitations in the monitoring system were identified. New standardized guidelines for monitoring safety and tolerability in antimalarial trials are needed, which should address how to detect events of greatest importance, including serious events, those with a causal relationship to the treatment, those which impact on adherence, and events not previously reported.

Conclusion

Although the World Health Organization has supported the development of pharmacovigilance systems in African countries deploying ACTs, additional guidance on adverse events monitoring in antimalarial clinical trials is needed, similar to the standardized recommendations available for assessment of drug efficacy.

Artemether-lumefantrine versus dihydroartemisinin-piperaquine for treating uncomplicated malaria: a randomized trial to guide policy in Uganda

Background

Uganda recently adopted artemether-lumefantrine (AL) as the recommended first-line treatment for uncomplicated malaria. However, AL has several limitations, including a twice-daily dosing regimen, recommendation for administration with fatty food, and a high risk of reinfection soon after therapy in high transmission areas. Dihydroartemisinin-piperaquine (DP) is a new alternative artemisinin-based combination therapy that is dosed once daily and has a long post-treatment prophylactic effect. We compared the efficacy and safety of AL with DP in Kanungu, an area of moderate malaria transmission.

Methodology/Principal Findings

Patients aged 6 months to 10 years with uncomplicated falciparum malaria were randomized to therapy and followed for 42 days. Genotyping was used to distinguish recrudescence from new infection. Of 414 patients enrolled, 408 completed follow-up. Compared to patients treated with artemether-lumefantrine, patients treated with dihydroartemisinin-piperaquine had a significantly lower risk of recurrent parasitaemia (33.2% vs. 12.2%; risk difference = 20.9%, 95% CI 13.0–28.8%) but no statistically significant difference in the risk of treatment failure due to recrudescence (5.8% vs. 2.0%; risk difference = 3.8%, 95% CI −0.2–7.8%). Patients treated with dihydroartemisinin-piperaquine also had a lower risk of developing gametocytaemia after therapy (4.2% vs. 10.6%, p = 0.01). Both drugs were safe and well tolerated.

Conclusions/Significance

DP is highly efficacious, and operationally preferable to AL because of a less intensive dosing schedule and requirements. Dihydroartemisinin-piperaquine should be considered for a role in the antimalarial treatment policy of Uganda.

Trial Registration

Controlled-Trials.com ISRCTN75606663

Artemether-lumefantrine versus dihydroartemisinin-piperaquine for treatment of malaria: a randomized trial

OBJECTIVES

To compare the efficacy and safety of artemether-lumefantrine (AL) and dihydroartemisinin-piperaquine (DP) for treating uncomplicated falciparum malaria in Uganda.

DESIGN

Randomized single-blinded clinical trial.

SETTING

Apac, Uganda, an area of very high malaria transmission intensity.

PARTICIPANTS

Children aged 6 mo to 10 y with uncomplicated falciparum malaria.

INTERVENTION

Treatment of malaria with AL or DP, each following standard 3-d dosing regimens.

OUTCOME MEASURES

Risks of recurrent parasitemia at 28 and 42 d, unadjusted and adjusted by genotyping to distinguish recrudescences and new infections.

RESULTS

Of 421 enrolled participants, 417 (99%) completed follow-up. The unadjusted risk of recurrent falciparum parasitemia was significantly lower for participants treated with DP than for those treated with AL after 28 d (11% versus 29%; risk difference [RD] 18%, 95% confidence interval [CI] 11%-26%) and 42 d (43% versus 53%; RD 9.6%, 95% CI 0%-19%) of follow-up. Similarly, the risk of recurrent parasitemia due to possible recrudescence (adjusted by genotyping) was significantly lower for participants treated with DP than for those treated with AL after 28 d (1.9% versus 8.9%; RD 7.0%, 95% CI 2.5%-12%) and 42 d (6.9% versus 16%; RD 9.5%, 95% CI 2.8%-16%). Patients treated with DP had a lower risk of recurrent parasitemia due to non-falciparum species, development of gametocytemia, and higher mean increase in hemoglobin compared to patients treated with AL. Both drugs were well tolerated; serious adverse events were uncommon and unrelated to study drugs.

CONCLUSION

DP was superior to AL for reducing the risk of recurrent parasitemia and gametocytemia, and provided improved hemoglobin recovery. DP thus appears to be a good alternative to AL as first-line treatment of uncomplicated malaria in Uganda. To maximize the benefit of artemisinin-based combination therapy in Africa, treatment should be integrated with aggressive strategies to reduce malaria transmission intensity.

Access to electronic health knowledge in five countries in Africa: a descriptive study

Background

Access to medical literature in developing countries is helped by open access publishing and initiatives to allow free access to subscription only journals. The effectiveness of these initiatives in Africa has not been assessed. This study describes awareness, reported use and factors influencing use of on-line medical literature via free access initiatives.

Methods

Descriptive study in four teaching hospitals in Cameroon, Nigeria, Tanzania and Uganda plus one externally funded research institution in The Gambia. Survey with postgraduate doctors and research scientists to determine Internet access patterns, reported awareness of on-line medical information and free access initiatives; semi structured interviews with a sub-sample of survey participants to explore factors influencing use.

Results

In the four African teaching hospitals, 70% of the 305 postgraduate doctors reported textbooks as their main source of information; 66% had used the Internet for health information in the last week. In two hospitals, Internet cafés were the main Internet access point. For researchers at the externally-funded research institution, electronic resources were their main source, and almost all had used the Internet in the last week. Across all 333 respondents, 90% had heard of PubMed, 78% of BMJ on line, 49% the Cochrane Library, 47% HINARI, and 19% BioMedCentral. HINARI use correlates with accessing the Internet on computers located in institutions. Qualitative data suggested there are difficulties logging into HINARI and that sometimes it is librarians that limit access to passwords.

Conclusion

Text books remain an important resource for postgraduate doctors in training. Internet use is common, but awareness of free-access initiatives is limited. HINARI and other initiatives could be more effective with strong institutional endorsement and management to promote and ensure access.

Artemisinin combination therapies for treatment of uncomplicated malaria in Uganda

Objectives:

To compare the efficacy and safety of artemisinin combination therapies for the treatment of uncomplicated falciparum malaria in Uganda.

Design:

Randomized single-blind controlled trial.

Setting:

Tororo, Uganda, an area of high-level malaria transmission.

Participants:

Children aged one to ten years with confirmed uncomplicated P. falciparum malaria.

Interventions:

Amodiaquine + artesunate or artemether–lumefantrine.

Outcome Measures:

Risks of recurrent symptomatic malaria and recurrent parasitemia at 28 days, unadjusted and adjusted by genotyping to distinguish recrudescences and new infections.

Results:

Of 408 participants enrolled, 403 with unadjusted efficacy outcomes were included in the per-protocol analysis. Both treatment regimens were highly efficacious; no recrudescences occurred in patients treated with amodiaquine + artesunate, and only two occurred in those treated with artemether–lumefantrine. However, recurrent malaria due to new infections was common. The unadjusted risk of recurrent symptomatic malaria was significantly lower for participants treated with artemether–lumefantrine than for those treated with amodiaquine + artesunate (27% versus 42%, risk difference 15%, 95% CI 5.9%–24.2%). Similar results were seen for the risk of recurrent parasitemia (51% artemether–lumefantrine versus 66% amodiaquine + artesunate, risk difference 16%, 95% CI 6.2%–25.2%). Amodiaquine + artesunate and artemether–lumefantrine were both well-tolerated. Serious adverse events were uncommon with both regimens.

Conclusions:

Amodiaquine + artesunate and artemether–lumefantrine were both highly efficacious for treatment of uncomplicated malaria. However, in this holoendemic area, despite the excellent performance of both regimens in terms of efficacy, many patients experienced recurrent parasitemia due to new infections. Artemether–lumefantrine was superior to amodiaquine + artesunate for prevention of new infections. To maximize the benefit of artemisinin combination therapy in Africa, treatment should be integrated with strategies to prevent malaria transmission. The impact of frequent repeated therapy on the efficacy, safety, and cost-effectiveness of new artemisinin regimens should be further investigated.

Background: Malaria parasites have become resistant in much of Africa to many commonly used treatments, such as chloroquine and sulfadoxine–pyrimethamine. Newer drugs, such as artemisinin-based combination therapies (ACTs), have been used extensively in Southeast Asia. Artemether–lumefantrine (an ACT) has now been adopted as first-line malaria treatment in Uganda, with the combination of amodiaquine and artesunate as a backup treatment. There are two ways that successful treatment is measured; first by whether the treatment works in curing the infection; and second by whether it prevents the disease recurring—either the same infection (known as recrudescence), or a new infection. The researchers wanted to look at how artemether–lumefantrine compared with amodiaquine and artesunate for treating symptomatic malaria, and also at whether there were any differences in recurrence, either of clinical malaria, or of parasite infection without symptoms, for 28 days after treatment.

What this trial shows: This randomized trial in young children with confirmed malaria in Uganda showed that both treatments resulted in a similar initial response to therapy, as measured by the risk of early treatment failure (within three days). The researchers found that artemether–lumefantrine was more effective at reducing the risk and delayed the time to recurrence of malaria, compared with amodiaquine and artesunate. Additionally, treatment with artemether–lumefantrine resulted in a reduced rate of parasite infection without malaria symptoms, as compared with amodiaquine and artesunate. Nearly all cases of recurrent malaria after either treatment combination arose from new infections, rather than from recrudescences.

Strengths and limitations: The trial was correctly designed to test the questions of interest, and enough patients were recruited to properly examine the relative effects of the two treatment combinations. However, patients were only followed up for 28 days after treatment. A longer follow-up period might have revealed a higher rate of recurrence of malaria after treatment. In the trial, artemether–lumefantrine was not administered with food, and it's known that lumefantrine is absorbed better when it is taken with a small amount of fat. It's possible that the effect of artemether–lumefantrine seen in the trial could have been an underestimate of what might be achieved in ideal conditions.

Contribution to the evidence: This trial adds information on the efficacy of artemether–lumefantrine as compared with amodiaquine and artesunate in East Africa for treatment of uncomplicated (i.e., non-severe) symptomatic malaria. The results are consistent with those of other trials on the efficacy of ACTs that have been performed in the region. The study also adds data on the risk of recurrent infections in an area where malaria occurs very frequently. Even following treatment with either ACT, the risk of recurrence was very high.

Sulfadoxine-pyrimethamine plus artesunate versus sulfadoxine-pyrimethamine plus amodiaquine for treating uncomplicated malaria

BACKGROUND

Artemisinin-based combination treatments are strongly advocated, but supplies are limited. Sulfadoxine combined with amodiaquine is an alternative non-artemisinin combination.

OBJECTIVES

To compare sulfadoxine-pyrimethamine plus amodiaquine (SP plus AQ) with sulfadoxine-pyrimethamine plus artesunate (SP plus AS) for treating uncomplicated Plasmodium falciparum malaria.

SEARCH STRATEGY

We searched the Cochrane Infectious Diseases Group Specialized Register (October 2005), CENTRAL (The Cochrane Library 2005, Issue 4), MEDLINE (1966 to October 2005), EMBASE (1988 to October 2005), LILACS (October 2005), and reference lists. We also contacted researchers and organizations working in this field.

SELECTION CRITERIA

Randomized controlled trials comparing SP plus AS with SP plus AQ for treating uncomplicated P. falciparum malaria.

DATA COLLECTION AND ANALYSIS

Two authors independently applied the inclusion criteria, extracted data, and assessed methodological quality. The primary outcome measure was treatment failure (parasitological or clinical evidence of treatment failure between start of treatment and day 28). We calculated the relative risk (RR) with 95% confidence intervals (CI) for dichotomous data.

MAIN RESULTS

Four trials (775 participants) met the inclusion criteria. All were from areas of high and seasonal malaria transmission in Africa. Fewer participants using SP plus AQ failed treatment by day 28 (RR 0.59, 95% CI 0.42 to 0.83; 652 participants, 3 trials). Even excluding new infections, SP plus AQ performed better (RR 0.62, 95% CI 0.40 to 0.96; 649 participants, 3 trials). There was no statistically significant difference between the two treatments for treatment failure at day 14 (RR 1.14, 95% CI 0.47 to 2.78; 775 participants, 4 trials). SP plus AS was more effective at reducing gametocyte carriage at day seven (RR 2.31, 95% CI 1.36 to 3.92; 220 participants, 1 trial). One trial reported that one person - in the SP plus AQ group - developed severe malaria. Adverse events were poorly reported, but did not seem to differ in type and number between the two treatment combinations.

AUTHORS' CONCLUSIONS

SP plus AQ performed better at controlling treatment failure at day 28, but was not as good as SP plus AS at reducing gametocyte carriage at day seven. Careful consideration of local resistance patterns is required because resistance to sulfadoxine-pyrimethamine and amodiaquine are high in many areas. In order to delay development of resistance to artesunate, the combination with sulfadoxine-pyrimethamine should only be considered where both drugs are known to be effective. Data on adverse events are still lacking.

Artesunate plus mefloquine versus mefloquine for treating uncomplicated malaria

BACKGROUND

Multiple-drug-resistant malaria is widespread, and in South-East Asia resistance is high against nearly all single therapy antimalarial drugs. Here, and in other areas with low malaria transmission, the combination of artesunate and mefloquine may provide an effective alternative.

OBJECTIVES

To compare artesunate plus mefloquine with mefloquine alone for treating uncomplicated Plasmodium falciparum malaria.

SEARCH STRATEGY

We searched the Cochrane Infectious Diseases Group Specialized Register (May 2005), CENTRAL (The Cochrane Library Issue 2, 2005), MEDLINE (1966 to May 2005), EMBASE (1988 to May 2005), LILACS (May 2005), BIOSIS (1985 to June 2005), conference proceedings, and reference lists. We also contacted researchers, organizations, and pharmaceutical companies.

SELECTION CRITERIA

Randomized and quasi-randomized controlled trials comparing artesunate plus mefloquine with mefloquine alone for treating uncomplicated malaria.

DATA COLLECTION AND ANALYSIS

Two authors independently applied the inclusion criteria, extracted data, and assessed methodological quality. The primary outcome was treatment failure by day 28, defined as evidence of parasitaemia with or without clinical failure between days zero (start of treatment) and 28. For dichotomous data we calculated relative risks (RR) and 95% confidence intervals (CI).

MAIN RESULTS

Eight trials involving 1996 participants met the inclusion criteria. All were conducted in areas with low malaria transmission, seven in South-East Asia and one in the Peruvian Amazon. The doses and dosing regimens of artesunate and mefloquine varied across trials. The trials using a total dose of 25 mg/kg mefloquine and 10 mg artesunate reported fewer treatment failures with the combination at all time points: day 28 (RR 0.17, 95% CI 0.06 to 0.47; 824 participants, 4 trials), day 42 (RR 0.23, 95% CI 0.14 to 0.39; 298 participants, 1 trial), and day 63 (RR 0.26, 95% CI 0.09 to 0.77; 501 participants, 2 trials). The results for parasitaemia showed a similar trend. Trials using a lower dose of artesunate tended to favour the artesunate plus mefloquine combination. Overall, adverse events were similar across treatment arms.

AUTHORS' CONCLUSIONS

Artesunate plus mefloquine performs better than mefloquine alone for treating uncomplicated falciparum malaria in areas with low malaria transmission. A total dose of 25 mg/kg mefloquine and at least 10 mg artesunate leads to higher cure rates. Better reporting of methods and standardisation of outcomes would help the interpretation of future trials.

Chlorproguanil-dapsone for treating uncomplicated malaria

BACKGROUND

In Africa, malaria is often resistant to chloroquine and sulfadoxine-pyrimethamine. Chlorproguanil-dapsone is a potential alternative.

OBJECTIVES

To compare chlorproguanil-dapsone with other antimalarial drugs for treating uncomplicated falciparum malaria.

SEARCH STRATEGY

We searched the Cochrane Infectious Diseases Group Specialized Register (May 2004), CENTRAL (The Cochrane Library Issue 2, 2004), MEDLINE (1966 to May 2004), EMBASE (1988 to May 2004), LILACS (May 2004), Biosis Previews (1985 to May 2004), conference proceedings, and reference lists, and contacted researchers working in this field.

SELECTION CRITERIA

Randomized and quasi-randomized controlled trials comparing chlorproguanil-dapsone to other antimalarial drugs.

DATA COLLECTION AND ANALYSIS

Two reviewers independently applied the inclusion criteria, extracted data, and assessed methodological quality. We calculated the relative risk (RR) for dichotomous data and weighted mean difference for continuous data, and presented them with 95% confidence intervals (CI).

MAIN RESULTS

Six trials (n = 3352) met the inclusion criteria. Chlorproguanil-dapsone (with 1.2 mg chlorproguanil) as a single dose had fewer treatment failures than chloroquine (1 trial), but more treatment failures and people with parasitaemia at day 28 than sulfadoxine-pyrimethamine (3 trials). Two trials compared the three-dose chlorproguanil-dapsone (with 2 mg chlorproguanil) regimen with sulfadoxine-pyrimethamine in new attendees. There were fewer treatment failures with chlorproguanil-dapsone by day 7 (RR 0.30, CI 0.19 to 0.49; n = 827, 1 trial) and day 14 (RR 0.36, CI 0.24 to 0.53; n = 1709, 1 trial). Neither trial reported total failures by day 28. A further trial was carried out in participants selected because they had previously failed sulfadoxine-pyrimethamine. Adverse event reporting was inconsistent between trials, but chlorproguanil-dapsone was associated with more adverse events leading to discontinuation of treatment compared with sulfadoxine-pyrimethamine (RR 4.54, CI 1.74 to 11.82; n = 829, 1 trial). It was also associated with more red blood cell disorders (RR 2.86, CI 1.33 to 6.13; n = 1850, 1 trial).

REVIEWERS' CONCLUSIONS

There are insufficient data about the effects of the current standard chlorproguanil-dapsone regimen (three-dose, 2 mg chlorproguanil). Randomized controlled trials that follow up to day 28, record adverse events, and use an intention-to-treat analysis are required to inform any policy decisions.